docs: def register_fields(w):
      """
      Register shapefile fields.
      """
      PARAMS_LIST = [BASE_PARAMS, GEOMETRY_PARAMS, MFD_PARAMS]
      for PARAMS in PARAMS_LIST:
          for _, param, dtype in PARAMS:
              w.field(param, fieldType=dtype, size=FIELD_SIZE)
  
      PARAMS_LIST = [
          RATE_PARAMS, STRIKE_PARAMS, DIP_PARAMS, RAKE_PARAMS, NPW_PARAMS,
          HDEPTH_PARAMS, HDW_PARAMS, PLANES_STRIKES_PARAM, PLANES_DIPS_PARAM]
      for PARAMS in PARAMS_LIST:
          for param, dtype in PARAMS:
              w.field(param, fieldType=dtype, size=FIELD_SIZE)
  
      # source typology
      w.field('sourcetype', 'C')